CMake find_package for non-standard locations - c++

Question

I am trying to make a self contained library whose dependencies are self contained.All installs are installed to <repo_dir>/libs//build.
To find dependencies in cmake build system I use find_package. Because all installs are in a custom location I point I use HINTS to help out like so -
# CMake 3.16.3
# ../lib/Catch2/build is where Catch2Config.cmake is located
find_package(Catch2 REQUIRED HINTS "../lib/Catch2/build" NO_MODULE)
include_directories(tests)
add_executable(tests tests.cpp)
target_link_libraries(tests PRIVATE project_warnings project_options Catch2::Catch2)
I recognize that Catch2 likely doesn't need this as it is header only, however I am trying to learn what cmake is doing.
The CMakeLists.txt above prints out
include could not find load file:
<repo_dir>/lib/Catch2/build/Catch2Targets.cmake │
Call Stack (most recent call first):
tests/CMakeLists.txt:1 (find_package)
It looks like a target file is needed as well. I cannot find one in the Catch2 repo.
I am also trying the same process for folly, however it does not work for me either.
Using the following in module mode for Boost worked. Why does it work?
set(CMAKE_INCLUDE_PATH ${CMAKE_INCLUDE_PATH} "${PROJECT_SOURCE_DIR}/lib/boost_1_75_0/")
set(CMAKE_LIBRARY_PATH ${CMAKE_LIBRARY_PATH} "${PROJECT_SOURCE_DIR}/lib/boost_1_75_0/libs")
find_package(Boost 1.60.0 REQUIRED)
include_directories(${Boost_INCLUDE_DIRS})
target_link_libraries(${CMAKE_PROJECT_NAME} ${Boost_LIBRARIES})
Could someone help to uncover my problems and how I should go about using
Header only libraries
Static lib binaries
Self-Compiled Libraries
Whose resources are in unusual places?